Transcript for NASA Connect - Rocket to The Stars

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Hey, hey, hey!

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I'm Kenan Thompson.

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But I play Fat Albert in
the live-action film based

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on Bill Cosby's hit show.

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On this episode of NASA Connect,

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you'll learn about the science
concepts of work and energy.

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You will also see how
we can use algebra

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to help explain both concepts.

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NASA engineers and scientists
will introduce you to exciting

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and innovative space propulsion
technologies of the future.

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And in your classroom, you'll
apply your math and science skills

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by conducting a really
cool hands-on activity.

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So stay tuned as host
Jennifer Pulley takes you

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on another exciting
episode of NASA Connect:

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"Rocket to the Stars."

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Hi, I'm Jennifer Pulley,
and welcome to NASA Connect,

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the show that connects you to math,

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science, technology, and NASA.

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Imagine it's the year 2040.

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You and a team of
international scientists are part

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of the exploration crew
that will begin construction

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of the first human base on Mars.

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You are laying the groundwork for
the next generation of explorers

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to explore Mars and beyond.

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It's not an easy task, but
you are up to the challenge.

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All your years of
schooling, training,

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and hard work have
finally paid off.

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Does it sound like
a fantasy to you?

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Actually, it's not.

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NASA is ready to make the next step

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to exploring the solar
system and beyond.

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And they need your help.

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NASA is looking for bright
young engineers, scientists,

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and researchers who
will make the new vision

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for space exploration a reality.

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For you, it starts right
now, in the classroom.

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Now, during the course of this
program, you will be asked

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to answer several
inquiry-based questions.

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After the questions
appear on the screen,

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your teacher will pause the
program to allow you time to answer

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and discuss the questions.

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This is your time to explore
and become critical thinkers.

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Students, working in
groups, take a few minutes

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to answer the following the
questions: One, what comes to mind

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when you think of work?

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Two, how are work
and energy related?

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Three, what are some
forms of energy?

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Briefly describe them and
give examples of each.

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It is now time to pause the
program and answer the questions.

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So, guys, how did you
do with the questions?

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Great job.

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Okay, let's get started.

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So what is work?

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Well, most people would say they
are working when they do anything

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that requires a physical...or
a mental effort.

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Now, in scientific terms,
work is the use of force

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to move an object
a certain distance.

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More specifically, to
do work on an object,

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some part of the force you exert
must be in the same direction

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as the object's motion.

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Let's look at the
following two examples.

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On the left side,
Norbert is lifting a stack

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of textbooks from the floor.

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And on the right side, he is
carrying the stack of textbooks.

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Note the direction of the applied
force and motion for each example.

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In which example is
Norbert actually doing work?

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If you said the left
side, you are correct.

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Why isn't Norbert doing work
in the example on the right?

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Well, because no part
of the applied force is

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in the same direction
as the object's motion.

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When the force is in the
same direction as the motion,

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we can determine the amount of
work being done on an object

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by multiplying force
times distance.

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What are the units for work?

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You know that force
is measured in newtons

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and distance can be
measured in meters.

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The product of a force measured in
newtons and the distance measured

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in meters is a measurement called
a newton-meter, or the joule.

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The joule is the standard
unit used to measure work.

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1 joule of work is
done when a force

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of 1 newton moves
an object 1 meter.

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Do you have any idea how
much a joule of work is?

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I know. Let's take an apple,
which weighs about 1 newton.

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Now, if you lift the apple
from the floor to your waist,

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which is about 1 meter, you do
1 joule of work on the apple.

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But what happens if I
want to lift 100 apples?

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For me, that would
take a lot of force,

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and I don't think I have
enough energy to do that.

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Let's go back to our
example with the apple.

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Now, I easily have enough energy
to lift this apple from the floor

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to my waist, and I know I'm doing
work on the apple as I lift it.

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So there must be a relationship
between work and energy, right?

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When I lifted the apple from
the floor, I caused a change.

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In this case, the change is
in the position of the apple.

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An object that has energy has
the ability to cause change

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or the ability to do work.

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When I "worked" on the apple,

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some of my energy was
transferred to the apple.

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You can think of work, then,
as the transfer of energy.

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As I lifted the apple from
the floor to my waist,

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the apple gained energy.

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You know, guys, energy has many
forms, and we'll get to your list

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in just a few minutes, but first
let's focus on two forms of energy:

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potential energy and
kinetic energy.

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Let's take a look at each.

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If I hold the apple still in my
hand, does the apple have energy?

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Careful; not all forms of
energy involve movement.

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Well, this apple has stored energy.

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We call it potential energy.

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Holding the apple like this
gives the apple the potential

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to fall to the ground.

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Now, if I release the
apple, the apple falls.

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The potential energy
changes into kinetic energy.

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It is pretty obvious when an
object has kinetic energy.

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As long as the object is moving,
it's said to have kinetic energy.

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What's more difficult to determine
is how much potential energy

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an object has.

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Let's go back to our
example with the apple.

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The potential energy of this apple
really depends on height, how high

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or low my hand is from the ground.

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We call this type of
potential energy gravitational

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potential energy.

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Gravitational potential
energy depends on mass,

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gravitational acceleration,
and height.

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Near the Earth's surface,
gravitational potential energy,

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or GPE, is equal to
the product of mass,

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gravitational acceleration,
and height.

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Remember that "g" is
the acceleration caused

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by Earth's gravity, which at
sea level equals 9.8 meters per

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second squared.

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Let me show you an example.

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Suppose a satellite has a mass
of 293 kilograms and we lift it

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to the top of Mount Everest.

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What is the gravitational
potential energy of the satellite?

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Well, what do we know?

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We know mass is equal
to 293 kilograms,

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gravitational acceleration is equal

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to 9.8 meters per second
squared, and we know the height

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of Mount Everest, which is
approximately 8,850 meters.

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Let's write the equation

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for gravitational potential
energy: GPE equals MGH.

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Substituting in our values for
mass, acceleration due to gravity,

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and height, we get: GPE equals
the product of 293 kilograms,

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9.8 meters per second
squared, and 8,850 meters.

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The answer turns out to be
approximately 25 million.

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Don't forget, I need to
assign a unit to that number.

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Units are very important when
explaining scientific concepts.

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Do you have any idea what
the unit for energy is?

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Let's figure it out.

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The original equation
for GPE is MGH.

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Mass times gravity
is equal to weight,

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and weight is measured in newtons.

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Remember, weight is a force.

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Therefore, the unit

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for gravitational potential
energy is the newton-meter.

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Do you remember from earlier

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in the program what a
newton-meter is equivalent to?

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Well, if you said 1
joule, you're on the ball.

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1 newton-meter is
equivalent to 1 joule.

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Wait a minute; work is
also measured in joules.

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I think we just showed
mathematically how energy

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and work are related to each other.

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Now let's go back
to kinetic energy.

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How much kinetic energy do
you think an object, say,

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like a rocket, depends on?

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The kinetic energy
of an object depends

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on both its mass and its velocity.

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The mathematical relationship
between kinetic energy, mass,

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and velocity is: KE
equals one-half MV squared.

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Notice that the velocity
is squared in the equation.

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Remember, guys, the number
2 is called an exponent.

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The exponent tells you
how many times a number

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or base is used as a factor.

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For example: two squared is equal

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to two times two,
which equals four.

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Three squared is equal
to three times three,

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which equals nine, and so on.

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The term "V squared" equals
V times V. So are you ready

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to try a problem involving
kinetic energy?

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Here's one for you.

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Norbert's Mars rover, with
a mass of 210 kilograms,

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is traveling on the
surface of Mars at a speed

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of 6 meters per second.

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Zot's rover, with a
mass of 170 kilograms,

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is traveling on the surface of
Mars at 8 meters per second.

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Predict which rover has
more kinetic energy.

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Then, verify your
prediction mathematically.

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You may now pause the program.

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So did you make the
correct prediction?

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Let's double-check your work.

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Solving for the kinetic energy
of Norbert's rover, we have:

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kinetic energy is equal to
one-half times 219 kilograms,

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times six meters per
second, quantity squared.

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The kinetic energy of Norbert's
rover is equal to 3,780 joules.

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Solving for the kinetic energy
of Zot's rover, we have:

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kinetic energy is equal to
one-half times 170 kilograms,

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times eight meters per
second, quantity squared.

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The kinetic energy of Zot's
rover is equal to 5,440 joules.

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So comparing the two values,
we see that the kinetic energy

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for Zot's rover is greater

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than the kinetic energy
for Norbert's rover.

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We now know that an object may
possess both kinetic energy

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and potential energy
at the same time.

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Let's go back to our
example with the apple.

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Any object that rises and
falls...experiences a change

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in its kinetic and
potential energy.

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Let's look at this
energy transformation

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as I toss the apple into the air.

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When the apple moves, it
possesses kinetic energy.

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As it rises, it slows down.

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Its kinetic energy decreases.

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Because the height increases,
its potential energy increases.

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At the highest point, the
apple actually stops moving.

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At this point, it no
longer has kinetic energy,

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but it has maximum
potential energy.

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As the apple falls, the
kinetic energy increases,

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and the potential energy decreases.

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No matter how energy is
transformed or transferred,

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all of the energy is still present
somewhere in one form or another.

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This statement is known as the
law of conservation of energy.

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As long as you account for all the
different forms of energy involved

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in any process, you will
find that the total amount

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of energy never changes.

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In other words, energy cannot
be created or destroyed.

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It just changes form.

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So, do you think you have a pretty
good idea of what work and energy,

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specifically potential and
kinetic energy, are all about?

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Well, good, because now it's time

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to preview this program's
hands-on activity.

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The NASA Explorer School students
from Martinsville Middle School

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in Martinsville, Virginia,

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will preview this
program's hands-on activity.

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Hi. NASA Connect asked us
to show you this program's

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hands-on activity.

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In this activity, students will
do an inquiry investigation

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on the relationship between
the height from which a marble

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on a ramp is released and the
distance a milk carton at the end

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of the ramp is moved
along the floor

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after the ball collides
with the carton.

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You can download a copy
of the educators' guide

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from the NASA Connect website for
directions and a list of materials.

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Before you start the activity,
your teacher will ask you to answer

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and discuss several
critical-thinking questions based

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on the experimental set-up.

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Set up the ramp by using tape to
mark one end 0.7 meters high up,

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and place an empty milk carton
at the other end of the ramp,

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so that it will catch the marble
after it rolls down the ramp.

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You will roll a marble from
five different measured heights.

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Line up a meter stick on
the floor along the distance

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that the milk carton will travel
after being hit by the marble.

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Starting at the first
height marked on the ramp,

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release the marble down the ramp.

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On the data collection
chart under "Trial 1,"

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record the linear distance
that the milk carton travels

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after the marble hit it.

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You will conduct four more trials.

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Record the distance the
milk carton travels.

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Calculate and record the average
distance the milk carton traveled.

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Continue the experiment
by increasing the height

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from which you drop the
marble by 0.1 meter each time.

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Students will analyze their data
by calculating the potential energy

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that the marble has at each
height and the kinetic energy

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that the marble has at
the end of each roll.

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Now is your chance to put your
algebra skills to the test.

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Keep in mind that for this
activity, you will need

[00:17:06.550]
to ignore energy lost
because of friction.

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Based on the data you collect,

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you will graphically show the
relationship between the height

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from which the marble is dropped

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and the distance the
carton is moved.

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From the graph, select
another designated height,

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and predict how far the
milk carton will move

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if the marble is released.

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Go ahead and test your prediction.

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Were you correct?

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Don't forget to check out the
web activity for this program.

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You can download it from
the NASA Connect website.

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Now that you have a basic
understanding of energy,

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let's hear about some
innovative propulsion technologies

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that NASA is developing for
future space exploration.

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And don't forget, you
are the future explorers.

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Thanks, Jennifer.

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Space is big.

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Distances to Mars and
beyond are so large

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that when using today's
spacecraft technology,

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we can only send relatively
small spacecraft.

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In other words, distance affects
the mass that we can send.

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NASA is working on a new way
of powering space vehicles

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that will enable us to send
more complex spacecraft to Mars,

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Jupiter, and beyond, and may
even shorten the travel time.

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The new program is
called Prometheus.

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It will provide a giant
leap in our ability

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to explore our solar system.

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The program focuses
on using nuclear power

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in long-distance spacecraft.

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The nuclear power system
will create electricity

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that will be used for two things.

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One job will be to
propel the spacecraft.

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The other will be to provide power
for the instruments on board.

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This capability will let NASA
send spacecraft to places

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that we currently want to reach.

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It would also allow us to
do more scientific work

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when the spacecraft
reaches its destination

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and could even help speed up
travel through the solar system.

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Many space missions
have used nuclear power.

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The farthest known man-made object
is the nuclear-powered spacecraft

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called Voyager 1.

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This probe has been
used for over 26 years.

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It is now over 8 billion
miles away.

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That's more than twice the
distance from the Sun to Pluto.

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Remember earlier in the
program, Jennifer asked you

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to list some forms of energy?

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On my list, I have mechanical
energy, thermal energy,

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chemical energy, electromagnetic
energy, and nuclear energy.

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Project Prometheus will
be using nuclear energy

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to help power the spacecraft.

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Nuclear energy is the energy
stored in the nucleus of an atom.

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In a nuclear reaction,
a tiny portion

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of an atom's mass is
turned into energy.

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Scientists are studying
two different ways

[00:19:56.480]
of using the energy stored
within the nucleus of an atom.

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The first approach
is to take an atom

[00:20:02.440]
that is naturally very unstable,
which means that the atom wants

[00:20:06.350]
to change into a different,
more stable atom.

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During this change, the atom
releases tiny particles,

[00:20:13.490]
causing the material to heat up.

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This process is known
as radioactive decay.

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The released particles
are called radiation.

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The heat that is released
can be harnessed

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and converted to electrical energy.

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This energy can then be used to
power the spacecraft systems.

[00:20:30.850]
It is called radioisotope decay.

[00:20:33.840]
The second approach is to break
apart the nucleus of the atom

[00:20:37.620]
to release even more energy
than radioactive decay.

[00:20:41.090]
This process is called
nuclear fission.

[00:20:43.970]
It is used in nuclear power
plants all around the world

[00:20:47.180]
to produce electricity.

[00:20:48.940]
Nuclear fission systems can
generate large amounts of power.

[00:20:53.100]
Think of this comparison.

[00:20:54.870]
A radioisotope power system
could create enough power

[00:20:58.280]
to light a few light bulbs.

[00:21:00.350]
A nuclear fission power system
could create enough energy

[00:21:04.000]
to power a laundromat.

[00:21:05.830]
This increased amount
of energy means

[00:21:07.810]
that a nuclear fission
energy system could do more

[00:21:11.280]
than just power a spacecraft's
scientific instruments.

[00:21:14.730]
It could also be used to run the
engines that propel the rocket.

[00:21:18.900]
NASA hopes to use
this technology soon.

[00:21:21.530]
In fact, it's already
working on the first probe

[00:21:24.030]
to use this technology.

[00:21:25.330]
This probe is the
Prometheus-1 mission.

[00:21:28.440]
This mission will use a
nuclear fission system.

[00:21:30.960]
This system would provide energy

[00:21:33.910]
for both spacecraft
electrical power and propulsion.

[00:21:37.800]
Prometheus-1 would orbit three
of the larger moons of Jupiter:

[00:21:42.150]
Callisto, Ganymede, and Europa.

[00:21:45.100]
Europa is one of our solar system's
most fascinating celestial bodies.

[00:21:49.840]
Europa's surface is
completely covered in ice,

[00:21:52.730]
but scientists believe that the
solar system's largest oceans could

[00:21:56.920]
be hidden under that ice.

[00:21:58.920]
If oceans are indeed present,
there is a possibility

[00:22:02.120]
that life could be found there.

[00:22:04.540]
The Pometheus-1 mission
will be finding answers

[00:22:07.310]
to the mysteries of these moons.

[00:22:09.560]
One day, the same power
and propulsion systems used

[00:22:12.550]
on Prometheus-1 could
be used to send probes

[00:22:15.650]
to other far-off places.

[00:22:18.040]
These systems will even be
used to support human missions

[00:22:21.030]
to explore the solar
system and beyond.

[00:22:23.610]
Back to you, Jennifer.

[00:22:25.810]
[00:22:27.450]
Thanks, Anita.

[00:22:28.620]
Sounds pretty cool.

[00:22:31.020]
You know, NASA is working on
another propulsion technology.

[00:22:34.940]
It's called VASIMR.

[00:22:36.770]
Dr. Franklin Chang-Diaz can tell
us more about that technology.

[00:22:40.790]
Thank you.

[00:22:44.290]
My name is Franklin Chang-Diaz.

[00:22:46.490]
I am an astronaut and director

[00:22:48.400]
of the Advanced Space
Propulsion Laboratory.

[00:22:50.880]
I would like to share with you
another possible advanced space

[00:22:54.470]
propulsion technology that we've
been working on for many years.

[00:22:58.240]
It is called the Variable Specific
Impulse Magnetoplasma Rocket,

[00:23:03.110]
or VASIMR for short.

[00:23:04.690]
This new engine would allow
for much faster space travel

[00:23:08.180]
than what we can do today.

[00:23:10.040]
VASIMR is a plasma-based
propulsion system.

[00:23:14.250]
Do you remember the
four states of matter?

[00:23:17.150]
They are: solid, liquid,
gas, and plasma.

[00:23:23.000]
You can go from one state
to the other by adding

[00:23:26.750]
or subtracting heat
from the material.

[00:23:29.690]
Take water, for example.

[00:23:31.340]
Its solid state is ice.

[00:23:33.790]
Add heat, and you get liquid.

[00:23:36.200]
Add more heat, and
you get gas or vapor.

[00:23:39.290]
If you add even more
heat to the gas,

[00:23:42.900]
the atoms in it get torn or broken.

[00:23:46.050]
Remember, each atom is sort of like
an egg: it has a central nucleus,

[00:23:51.590]
the yoke, with positive
particles in it called protons;

[00:23:56.390]
and a blanket, the white,

[00:23:58.840]
of negative-charged particles
called electrons in it.

[00:24:03.500]
When the atom gets torn,
these charges are free to roam

[00:24:07.760]
around every which way.

[00:24:10.700]
Scrambled eggs.

[00:24:12.980]
Such a mixture of charged
particles is called plasma.

[00:24:18.110]
Plasmas are very hot, with
temperatures of hundreds

[00:24:21.760]
of thousands to millions
of degrees.

[00:24:25.100]
The Sun and the stars
are made of plasma.

[00:24:28.970]
Plasmas are very good
conductors of electricity,

[00:24:32.080]
and they respond very well to
electric and magnetic fields.

[00:24:37.180]
We use these properties to heat
them and also to confine them

[00:24:42.650]
and use their extreme heat to
produce awesome rocket propulsion.

[00:24:48.250]
Electric fields heat the
plasma and speed it up.

[00:24:52.400]
Magnetic fields direct the
plasma in the right direction

[00:24:56.520]
as it is pushed out of the engine.

[00:24:58.900]
This creates thrust
for the spacecraft.

[00:25:02.130]
Possible fuels for the VASIMR
engine could include hydrogen,

[00:25:07.470]
deuterium, helium,
nitrogen, and others.

[00:25:12.250]
The use of hydrogen as a fuel

[00:25:15.190]
for the project would
also have other benefits.

[00:25:19.080]
Hydrogen can be found
all throughout space.

[00:25:22.940]
This means we are likely
to find plentiful supplies

[00:25:26.470]
of fuel everywhere we go, and
we could refuel the spacecraft

[00:25:31.770]
for the return trip to Earth.

[00:25:34.130]
Also, strong magnetic fields
and liquid hydrogen make

[00:25:38.740]
for great radiation shields.

[00:25:41.360]
This means the hydrogen
fuel for the VASIMR engine,

[00:25:45.140]
as well as the magnet technology
we are developing for it,

[00:25:50.000]
could both also be used to
protect the astronaut crew

[00:25:55.070]
from dangerous radiation
exposure during the flight.

[00:25:58.810]
This is how technology developed
for one thing can also be used

[00:26:04.100]
for another equally
important purpose.

[00:26:07.220]
To heat and accelerate the
plasma in deep-space flights,

[00:26:12.340]
VASIMR will use electricity
from nuclear power.

[00:26:17.040]
VASIMR is still years away
from transporting humans

[00:26:22.270]
and cargo to Mars and beyond.

[00:26:25.420]
Remember the scenario
that Jennifer gave you

[00:26:28.250]
at the beginning of the program.

[00:26:30.290]
Our team can only take this
advanced technology so far.

[00:26:35.280]
And then it will be up to you.

[00:26:37.400]
Your generation will make this
space propulsion system a reality.

[00:26:43.320]
Some of you may one day fly on
it and become the astronauts

[00:26:47.700]
that will build the
first base on Mars.

[00:26:51.050]
I've been in space seven times,
but you will be the astronauts

[00:26:55.840]
who will get a chance to explore
the moon, Mars, and beyond.

[00:27:00.930]
You are the next generation
of explorers.

[00:27:03.870]
So, good luck.

[00:27:06.290]
Back to you, Jennifer.

[00:27:08.220]
[00:27:09.850]
My thanks, Dr. Chang-Diaz.

[00:27:12.040]
You know, I can't wait for the day

[00:27:14.020]
when we receive the first
transmission from people on Mars,

[00:27:18.340]
and maybe you'll be one of them.

[00:27:20.450]
Well, that wraps up another
episode of NASA Connect.

[00:27:24.280]
We'd like to thank everyone who
helped make this program possible.

[00:27:27.840]
Got a comment, question,
or suggestion?

[00:27:30.570]
Well, email them to
"connect at larc.nasa.gov."

[00:27:36.200]
And don't forget to check out
this program's student challenge.

[00:27:40.410]
You can find it on the
NASA Connect website.

[00:27:43.350]
So until next time,
stay connected to math,

[00:27:46.530]
science, technology, and NASA.

[00:27:49.850]
And maybe we'll see you on Mars.

[00:27:52.130]